tracing: Trivial updates for 6.11

- Set rtla/osnoise default threshold to 1us from 5us
   The 5us default was missing noise that people cared about.
   Changing it to 1us makes it work as expected.
 
 - Restructure how sched_switch prev_comm and next_comm was being saved.
   The prev_comm was being saved along with the other next fields, and the
   next_comm was being saved along with the other prev fields. This is just
   a cosmetic change.
 
 - Have the allocation of pid_list use GFP_NOWAIT instead of GFP_KERNEL.
   The allocation can happen in irq_work context, but luckily, the size
   was by default so large, it was never triggered. But in case it ever is,
   use the NOWAIT allocation in the interrupt context.
 
 - Fix some kernel doc errors.
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Merge tag 'trace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:
 "Trivial updates for 6.11:

   - Set rtla/osnoise default threshold to 1us from 5us

     The 5us default was missing noise that people cared about. Changing
     it to 1us makes it work as expected.

   - Restructure how sched_switch prev_comm and next_comm was being saved

     The prev_comm was being saved along with the other next fields, and
     the next_comm was being saved along with the other prev fields.
     This is just a cosmetic change.

   - Have the allocation of pid_list use GFP_NOWAIT instead of GFP_KERNEL

     The allocation can happen in irq_work context, but luckily, the
     size was by default so large, it was never triggered. But in case
     it ever is, use the NOWAIT allocation in the interrupt context.

   - Fix some kernel doc errors"

* tag 'trace-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  trace/pid_list: Change gfp flags in pid_list_fill_irq()
  tracing/sched: sched_switch: place prev_comm and next_comm in right order
  rtla/osnoise: set the default threshold to 1us
  tracing: Fix trace_pid_list_free() kernel-doc
This commit is contained in:
Linus Torvalds 2024-07-18 13:29:25 -07:00
commit 2fd4130e53
4 changed files with 8 additions and 7 deletions

View File

@ -108,7 +108,7 @@ The tracer has a set of options inside the osnoise directory, they are:
option.
- tracing_threshold: the minimum delta between two time() reads to be
considered as noise, in us. When set to 0, the default value will
be used, which is currently 5 us.
be used, which is currently 1 us.
- osnoise/options: a set of on/off options that can be enabled by
writing the option name to the file or disabled by writing the option
name preceded with the 'NO\_' prefix. For example, writing

View File

@ -239,11 +239,11 @@ TRACE_EVENT(sched_switch,
),
TP_fast_assign(
memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
__entry->prev_pid = prev->pid;
__entry->prev_prio = prev->prio;
__entry->prev_state = __trace_sched_switch_state(preempt, prev_state, prev);
memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
__entry->next_pid = next->pid;
__entry->next_prio = next->prio;
/* XXX SCHED_DEADLINE */

View File

@ -354,7 +354,7 @@ static void pid_list_refill_irq(struct irq_work *iwork)
while (upper_count-- > 0) {
union upper_chunk *chunk;
chunk = kzalloc(sizeof(*chunk), GFP_KERNEL);
chunk = kzalloc(sizeof(*chunk), GFP_NOWAIT);
if (!chunk)
break;
*upper_next = chunk;
@ -365,7 +365,7 @@ static void pid_list_refill_irq(struct irq_work *iwork)
while (lower_count-- > 0) {
union lower_chunk *chunk;
chunk = kzalloc(sizeof(*chunk), GFP_KERNEL);
chunk = kzalloc(sizeof(*chunk), GFP_NOWAIT);
if (!chunk)
break;
*lower_next = chunk;
@ -451,6 +451,7 @@ struct trace_pid_list *trace_pid_list_alloc(void)
/**
* trace_pid_list_free - Frees an allocated pid_list.
* @pid_list: The pid list to free.
*
* Frees the memory for a pid_list that was allocated.
*/

View File

@ -1444,9 +1444,9 @@ static int run_osnoise(void)
save_osn_sample_stats(osn_var, &s);
/*
* if threshold is 0, use the default value of 5 us.
* if threshold is 0, use the default value of 1 us.
*/
threshold = tracing_thresh ? : 5000;
threshold = tracing_thresh ? : 1000;
/*
* Apply PREEMPT and IRQ disabled options.